In recent years, an electric vehicle, a hybrid vehicle, a fuel cell vehicle and the like have been receiving attention as environmentally friendly vehicles. These vehicles incorporate a motor for generating a driving force for traveling, and a power storage device for storing electric power supplied to the motor. A hybrid vehicle further incorporates an internal combustion engine together with the motor as a mechanical power source, and a fuel cell vehicle incorporates a fuel cell as a direct current (DC) power supply for driving the vehicle.
Among these vehicles, a vehicle is known in which a vehicle-mounted power storage device for driving the vehicle can be charged by a power supply in an ordinary household. Electric power is supplied from the power supply in the ordinary household to the power storage device by connecting a power supply outlet provided in a house to a charging port provided on the vehicle through a charging cable, for example. It is noted that such vehicle in which the vehicle-mounted power storage device can be charged by the power supply outside of the vehicle will also be hereinafter referred to as “plug-in vehicle.”
Japanese Patent Laying-Open No. 2009-71989 (Patent Document 1) discloses a technique about charging of such plug-in vehicle. This plug-in vehicle can conduct communication with a charging station and the like by using a pilot signal during charging, and detect a break in a control line for communicating the pilot signal.